A 3D FEM Comparison of Labial and Lingual Orthodontics for Maxillary Midline Diastema Closure

Abstract

Introduction: Lingual orthodontics is gaining popularity day by day. However very few information is present in literature regarding physiologic reaction that occurs after force application, efficacy and rate of tooth movement in lingual orthodontics when compared with labial orthodontics. Aim: This study was designed for comparison of aforesaid parameters in midline diastema cases with both lingual as well as labial orthodontics. Materials and Methods: Cone-beam computed tomography scanning was used to create geometric models for maxillary central incisors. Two 3D finite element models of maxillary central incisors having diastema, bonded with 0.018” brackets, labially and lingually with 0.017”×0.025” SS arch wires placed was constructed. These models were then meshed and analysed with commercially available finite-element analysis software. Diastema closure was simulated by applying 50 gm of mesial force from maxillary right central incisor to maxillary left central incisor. Software was used to compare the stress in periodontium, efficacy and rate of the instantaneous displacement of tooth (maxillary right and left central incisor) under labial and lingual loading during the midline diastema closure retraction. Results: More stress and displacement of teeth for closing the gap can be observed for labial loading compared to the lingual loading. Conclusion: By applying equal force labially and lingually, more bodily movement is seen in labial mechanics whereas lingual mechanics shows mesial crown tipping as well as bodily movement.

Keywords

• computer simulation
• finite element analysis
• orthodontic space closure
• spacing
• stress